Micro-robots pirouette on 1mm dance floor

Washington, June 3 : A Duke University computer scientist has achieved a major success in assembling microscopic robots crafted to manoeuvre separately into self-organised structures.

"It's marvelous to be able to do assembly and control at this fine a resolution with such very, very tiny things," said Bruce Donald, a Duke professor of computer science and biochemistry.

He says that each robot is shaped something like a spatula, and is almost 100 times smaller than any previous robotic designs of their kind.

He has also revealed that the devices, formally known as microelectromechanical system (MEMS) microrobots, are suitable for performing Lilliputian tasks like moving around the interiors of laboratories-on-a-chip.

His team has also produced videos that show two microrobots pirouetting to the music of a Strauss waltz on a dance floor just one millimetre across.

The videos also show the dices pivoting in a precise fashion whenever their boom-like steering arms are drawn down to the surface by an electric charge.

Donald likens this response to the way dirt bikers turn by extending a boot heel.

He says that his group's latest accomplishment is getting five of the devices to group-manoeuvre in co-operation under the same control system.

"Our work constitutes the first implementation of an untethered, multi-microrobotic system," Donald's team writes in a report to be presented on June 1-2, 2008 during the Hilton Head Workshop on Solid State Sensors, Actuators and Microsystems in South Carolina.

The researchers write in their report that five of the microrobots can be made to advance, turn and circle together in pre-planned ways when each is built with slightly different dimensions and stiffness.

"Initially, we wanted to build something like a car that could drive around at the microscopic scale. Now what we've been able to do is create the first microscopic traffic jam," Donald says.

He revealed that he and his colleagues worked really hard from 1997 to 2002 to create a microbot that could operate without a tether, then three more years to make the devices steer under global control, and finally another three years to independently manoeuvre more than one at a time.

"The hard thing was designing how multiple microrobots can all work independently, even while they receive the same power and control," he said.

A detailed article on the researchers' work is set for publication in the Journal of Microelectromechanical Systems.